Absolute Hammer load data

[stevejfarms]

Did a little more load testing today.
257 Weatherby
26" 10 twist
once fired Hornady brass
Fed 215
COAL 3.170
90 gr AH

IMR 4350
67.5 3788
68.0 3810
68.5 3856 slight ejector
69.0 3895 ejector slightly heavy bolt stuck case

Rl 26
70.0 3493
71.0 3561
72.0 3618
73.0 3740
74.0 3800
74.5 3855 stuck case


26 Nosler
26" 8 twist
New Nosler brass
WLRM primer
COAL 3.450
fcd 1/8 turn
129 gr AH
H4831

75.0 3340
76.0 3401
77.0 3452 ejector
78.0 3468 bright ejector, bolt lift


280 ai
22" 9 twist
once fired nosler brass
Fed 215
COAL 3.410
140 gr AH
IMR 4350
56.0 2931
57.0 3015
58.0 3089 slight ejector
59.0 3141 "
60.0 3220. "
61.0 3257. bright ejector
62.0 3304. bright ejector
63.0 3348. blown primer!!
I was surprised by the blown primer, the bolt lifted easily after the shot. There was very bright sunshine and the ejector marks were shinier than I thought in the glare. I need to be more careful.

 

[RogerPA]

Has anyone else noticed how frequently there's a point in the Absolute Hammer load development where 1.0 or even .5 grain will suddenly bring a jump of around 100 FPS? It then seem pressure signs begin showing up within 2 or 3 grains from this point. (?). I certainly have observed this with my own experiments, and after studying the other entries in the spreadsheet, this seems to be a common occurrence.

 

[ButterBean]

Has anyone else noticed how frequently there's a point in the Absolute Hammer load development where 1.0 or even .5 grain will suddenly bring a jump of around 100 FPS? It then seem pressure signs begin showing up within 2 or 3 grains from this point. (?). I certainly have observed this with my own experiments, and after studying the other entries in the spreadsheet, this seems to be a common occurrence.

I concur

 

[GLTaylor]

I agree. It seems there's a pressure and speed jump. At first I thought it was an anomoly, but I've seen it more than once now. Pressuring out (safely) also seems to occur quickly afterwards. Maybe sooner than within 2 grains. JMO

 

[cooperjd]

When y'all are settling in on a load... are you looking for zero signs of pressure and calling it safe? Or do you accept maybe a small ejector swipe or cratered primer as acceptable so long as the heavy ejector marks and heavy bolts are a couple-few grains more? In projectiles designed to run hot, how hot is acceptable i guess? I've been loading for quite a few years but never chased velocities like with the AH's.

 

[ButterBean]

When y'all are settling in on a load... are you looking for zero signs of pressure and calling it safe? Or do you accept maybe a small ejector swipe or cratered primer as acceptable so long as the heavy ejector marks and heavy bolts are a couple-few grains more? In projectiles designed to run hot, how hot is acceptable i guess? I've been loading for quite a few years but never chased velocities like with the AH's.

I always have a light ejector mark

 

[NorCalRiceGuy]

When y'all are settling in on a load... are you looking for zero signs of pressure and calling it safe? Or do you accept maybe a small ejector swipe or cratered primer as acceptable so long as the heavy ejector marks and heavy bolts are a couple-few grains more? In projectiles designed to run hot, how hot is acceptable i guess? I've been loading for quite a few years but never chased velocities like with the AH's.

I think that, like most issues here, every gun and powder will be different. Some will run hot for best accuracy and others won't. Let the individual gun's accuracy node(s) dictate rather than have a "blanket" approach.

 

[dougduey]

When y'all are settling in on a load... are you looking for zero signs of pressure and calling it safe? Or do you accept maybe a small ejector swipe or cratered primer as acceptable so long as the heavy ejector marks and heavy bolts are a couple-few grains more? In projectiles designed to run hot, how hot is acceptable i guess? I've been loading for quite a few years but never chased velocities like with the AH's.

I usually go until I get some sort of ejector mark and a slight stiff bolt lift, then I back off at least 1 gr from there. That's always been safe for me

 

[cooperjd]

I think that, like most issues here, every gun and powder will be different. Some will run hot for best accuracy and others won't. Let the individual gun's accuracy dictate rather than have a "blanket" approach.

True, something extremely fast but shooting 2moa isn't acceptable. i should've been more clear. Since these bullets are designed to be pushed, and I should've said if you find a load that is fast and accurate, what is an acceptable level of pressure signs to shoot regularly. Just wanna make sure i'm not doing something dumb

My .300wby dies delivered yesterday. Hopefully I will have some 178AH data next week sometime.

 

[ButterBean]

True, something extremely fast but shooting 2moa isn't acceptable. i should've been more clear. Since these bullets are designed to be pushed, and I should've said if you find a load that is fast and accurate, what is an acceptable level of pressure signs to shoot regularly. Just wanna make sure i'm not doing something dumb

My .300wby dies delivered yesterday. Hopefully I will have some 178AH data next week sometime.

I've never had a Hammer that wouldn't group at any velocity yet

 

[Bob Wright]

I agree. It seems there's a pressure and speed jump. At first I thought it was an anomoly, but I've seen it more than once now. Pressuring out (safely) also seems to occur quickly afterwards. Maybe sooner than within 2 grains. JMO

I copied and pasted in previous comments on the Absolutes, an article about "secondary pressure events". I believe the comments of sudden velocity/pressure signs in brass at a .5 grain or more fits this specific bullet peculiarities. Finding the right powder to continually support the linear rate of acceleration to build and not drop off internally is what your challenge may be. There is no testing to prove except reading brass and recording velocities is critical. If it's spiking 100fps in .5 grain, I would reassess at least powder choices, possibly crimping like Butterbean does. Many of the users are getting great results and their load data/processes are the reason why. It is an amazing design in the Absolute that takes a bit of testing to get what you want.

 

[GLTaylor]

I don't have a FCDie for all my calibers (wildcats). Where I do, this seems beneficial regarding incremental pressure increases. Speeds seem to improve by 10-30 or so fps. BBean is more the authority here. He has done tons more testing and may offer insight.

Hammers are the most forgiving bullet I've ever shot regarding seating and overall accuracy. They do not vary bullet to bullet (CNC turned). Having said that, powder charge DOES seem to affect accuracy. My minimum acceptable accuracy level is 0.5 moa. It is not uncommon to back off of charge 1/2 to 1 grain below max velocity to shoot nice round clusters.
If 1 moa is good for you - Hammers will frequently do that well at max velocity
I also usually have visible light ejector swipe when I quit. I do NOT like any bolt lift whatsoever. JMO

 

[CMP70306]

So how would you rate the pressure signs here? This was 58.3, 58.6 and 58.9gr StaBall 6.5 with the 123 AH in my brother's 6.5 PRC Xbolt 2.925 COAL with a Lee FCD tightened to the second notch. I'm wondering why the ejector mark disappeared from 58.3 to 58.6 but reappeared at 58.9. Based on the accuracy and ES/SD 58.6 is the go to load for both rifles I tested last weekend.

Also I think I'm going to try IMR 4955 with the 123gr AH, I had speed previously with Superformance but was looking to avoid the temp issues and it's right next to it on the burn chart.

 

[GLTaylor]

Lighting isn't great, but all but bottom right appear ok to me. Bottom right seems to show a pronounced ejector indention. If that's so, it would be pretty hot and hard on your rifle. I personally wouldn't shoot one that hot.